Ashwagandha (Withania somnifera) is a short shrub native to India and Nepal. Also known as Indian ginseng, poison gooseberry and winter cherry, ashwagandha is a member of the nightshade family (along with eggplant and tomatoes).
Virtually all parts of the plant have been used either in cooking or medicinally. The red berries of the plant have been used in cheesemaking as a substitute for rennet, which curdles the milk.
Medicinally, the leaves and roots are the two parts most commonly used. The leaves are known to contain alkaloids, compounds used throughout history recreationally (think opium and cocaine), as well as medicinally (morphine).
The leaves also contain steroidal compounds known as withanolides, the most common of which is withaferin A. Withaferin A has been shown to inhibit angiogenesis, or the formation of new blood vessels.1 This is critical for conditions such as cancer and the wet form of macular degeneration.
Withaferin A also inhibits nuclear factor kappa B (NF-KB)1 and down regulates VEGF gene expression.2 This is important because NF-KB is a biomarker of free radical damage and inflammation. The VEGF gene is involved in angiogenesis, particularly when it involves the formation of tumors. By down regulating its expression, you can work to prevent the spread of cancer.
The roots are typically used to treat stress and anxiety, as well as brain health and energy.
Conditions Supported by Ashwagandha
- Brain health
- Depression and anxiety
- Eye health
What Does the Research Say?
Ashwagandha appears to support brain health in a number of ways, including memory loss, cognition, brain damage and neurodegenerative diseases.
In one study published in a 2005 issue of the British Journal of Pharmacology, researchers found that this herb helped mice with brain damage and memory loss to recover memory and regenerate their neurons and synapses.3
A May 2003 study showed that ashwagandha protected the brain by acting as an antioxidant,4 while a review published in 2011 mentions its usefulness against neurodegenerative conditions such as Parkinson’s, Huntington’s and Alzheimer’s diseases.5-6
Similarly, researchers found that Withania somnifera modulates Alzheimer’s disease pathology, according to a study published in February 2012.7 The study used transgenic mice with accelerated Alzheimer’s disease pathology and beta-amyloid plaque deposition, which is implicated in the development of Alzheimer’s disease. The mice received Withania somnifera root extract for 30 days.
Withania somnifera administration resulted in reversal of behavioral deficits, plaque pathology and accumulation of beta-amyloid peptides in the brains of middle-aged and old mice. In addition, after seven days of Withania somnifera administration, beta-amyloid peptides were increased in the plasma and decreased in the brain, indicating increased transport of the peptides from the brain to the periphery.
Also after seven days, there was an increase in low-density lipoprotein receptor-related protein and the beta-amyloid peptide-degrading protease neprilysin in the liver and a rise in plasma soluble low-density lipoprotein receptor-related protein. After 14 to 21 days of declining beta-amyloid peptides in the brain, the researchers found an increase in the expression of low-density lipoprotein receptor-related protein in brain microvessels and neprilysin. The researchers state that this promotes clearance of brain beta-amyloid peptides.
The investigators concluded, “The remarkable therapeutic effect of Withania somnifera mediated through up-regulation of liver low-density lipoprotein receptor-related protein indicates that targeting the periphery offers a unique mechanism for beta-amyloid peptide clearance and reverses the behavioral deficits and pathology seen in Alzheimer’s disease models.”
Depression and Anxiety
Research suggests that ashwagandha exhibits anti-anxiety and antidepressant activity comparable to pharmaceutical agents.8
In fact, one randomized, placebo-controlled, double-blind study published in 2009 found that people with severe anxiety who used ashwagandha experienced a significant decrease in symptoms, as compared to those who received more traditional care.9
Researchers divided 75 people with moderate to severe anxiety of longer than six weeks duration into two groups. The first received naturopathic care (NC), which consisted of dietary counseling, deep breathing relaxation techniques, a standard multivitamin and 300 mg of ashwagandha, standardized to 1.5% with anolides. The second group received standardized psychotherapy (PT), which included psychotherapy, matched deep breathing relaxation techniques and placebo.
Researchers used the Beck Anxiety Inventory (BAI), the Short Form 36 (SF-36), Fatigue Symptom Inventory (FSI) and Measure Yourself Medical Outcomes Profile (MY-MOP) to measure anxiety, mental health and quality of life.
After eight+ weeks, researchers found that those in the ashwagandha group enjoyed a 56 percent reduction in BAI scores, as compared to 30 percent in the conventional group. Significant differences in mental health, concentration, fatigue, social functioning, vitality and overall quality of life were also observed, with those in the ashwagandha group seeing a greater benefit.
Researchers concluded, “Group comparison demonstrated a significant decrease in anxiety levels in the NC group over the PT group. Significant improvements in secondary quality of life measures were also observed in the NC group as compared to PT.”
While there isn’t a vast body of research on ashwagandha for eye health, traditional use indicates that the root powder of ashwagandha with fruit powder of amalaki (also known as Indian gooseberry) and cardamom—a tropical spice of the ginger family—mixed with honey can help preserve visual acuity and eyesight.10
Ashwagandha may be best known for its ability to help the body adapt to stress, as well as its ability to regulate the production of cortisol-releasing factor in the brain. It does this, in large part, because of its adaptogenic properties.
Adaptogens are a type of botanical that support the adrenal glands. Not only do they help to boost your energy levels, but they have also been shown to balance cortisol levels and help reduce your response to stress.11-14
Specifically, ashwagandha has been shown in a number of animal studies to reduce the effects of stress,15-16 indicating it may help people who are prone to stress-related eating or whose excess pounds are due to unbalanced cortisol levels.
One animal study investigated the anxiety-lowering and antidepressant actions of the bioactive Withania somnifera glycowithanolides (WSG) isolated from Withania somnifera roots. Withania somnifera glycowithanolides (20 and 50 mg/kg) was administered orally once a day for five days, and the results were compared by those elicited by an anti-anxiety drug and by a tricyclic antidepressant.
The results showed that WSG induced an anti-anxiety effect comparable to the anti-anxiety drug when the rats were forced to navigate a maze, be involved in social interaction, and endure delayed feeding in an unfamiliar environment. In addition, both WSG and the anti-anxiety drug reduced rat brain levels of tribulin, a marker of clinical anxiety. WSG also exhibited an antidepressant effect, comparable with that induced by the tricyclic antidepressant, during a test where the rats were forced to swim.17
Additional research shows that ashwagandha also soothes the body’s stress response, while providing strong natural support for your endocrine, central nervous and cardiovascular systems.18
How to Use Ashwagandha
Based on the research, the average recommended dosage for ashwagandha is 100-200 mg twice a day.
There are no significant side effects associated with ashwagandha.9,19
- Mohan R, et al. Angiogenesis. 2004;7(2):115-22.
- Prasanna Kumar S, et al. Curr Trends Biotechnol Pharm. 2009;3(2):138-48.
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- Chaudhary G, et al. Clin Exp Pharmacol Physiol. 2003 May-Jun;30(5-6):399-404.
- Narendra Singh, et al. Afr J Tradit Complement Altern Med. 2011; 8(5S): 208–13.
- Ven Murthy MR, et al. Cent Nerv Syst Agents Med Chem. 2010 Sep 1;10(3):238-46.
- Sehgal N, et al. Proc Natl Acad Sci U S A. 2012;9:3510-5.
- Villaverde Gutierrez C, et al. J Clin Nurs. 2012;7-8:923-8.
- Cooley K, et al. PLoS One. 2009 Aug 31;4(8):e6628.
- “Ashwagandha: Elixir par excellence,” Complete Wellbeing, completewellbeing.com/article/ashwagandha-elixir-par-excellence/.
- Kour K, et al. Int Immunopharmacol. 2009 Sep;9(10):1137-44.
- Kuo J, et al. Chin J Physiol. 2010 Apr 30;53(2):105-11.
- Shevtsov VA, et al. Phytomedicine. 2003;10:95-105.
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- Bhattacharya, S et al. Phytother Res 1987;1:32-37.
- Ghosal, S et al. Phytother Res 1989;3:201-6.
- Bhattacharya SK, et al. Phytomedicine 2000 Dec;7(6):463-9.
- Mishra LC, et al. Altern Med Rev. 2000 Aug;5(4):334-46.
- Chopra A, et al. J Clin Rheumatol. 2004 Oct;10(5):236-45.